Washing of discharge prints



Patented Feb. 13, 1940 PATENT. OFFICE WASHING F DISCHARGE PRINTS Samuel Lenher. and Joseph E. Smith, Wilmington, DeL, assignors to E. I. du Pont de Nemours 85 Company, Wilmington, Del., a corporation of Delaware No Drawing.

14 Claims.

This invention relates to the washing of -tex' tile materials, more particularly it relates to the washing of fabrics dyedwith water-soluble dyes,

still more particularly it relates to the washing of textile fabrics dyed with azo colors. In a more limited sense the invention pertains to discharge printing and to the washing of discharge prints of the white and'colored type. In a preferred embodiment the invention relates to the washing of discharge prints on cotton and viscose rayon in which azo dyes are used in the ground shades. :The invention also relates to washing solutions and to "washing compositions.

Discharge prints are of two types: white, and colored. In preparing a discharge print, dyeings are first made of a color which can be reduced by the discharge agent. This dye, known as the ground color, is usually of the azo type. In white discharge printing, the dyed goods are printed with a gum paste containing sodium sulfoxylate formaldehyde (Na2SO2-CH2O|2H2O) The printed goods are aged in an atmosphere .of steam at -'100'-105 C. for about five minutes. 'Underthese conditions NazSO2 is liberated and in turn acts to reduce the dye into aminoand hydroxyaromatic bodies. The print is washed to remove the products of the discharge, frequently quite yellow in color, and the discharge paste. In practice, the methods of Washing vary widely, depending largely on the fastness of the ground color. The wash solution may vary from water alone, to a 0.5% solution of a detergent such as the fatty alcohol sulfates or soap. I he temperatures may vary between room temperature and 160-180 F. The time may vary from a minute'to a half hour.- In all cases the conditions selected by the processor are the result of a compromise.

is possible without removing appreciable quan- 40 tities of the ground color. In practice, it is not unusual for 20% of the dye to be removed from thegoods. not only because of loss of strength of the dyeing, but also because the dye removed into the bath'shows a marked tendency to stain the discharged portions of the print.

In, colored discharge printing, a dye which is applicable to the goods under the discharge conditions is incorporated, together with the sodium sulfoxylate formaldehyde in the printing paste. Vat colors are customarily used. Under the aging conditions outlined above, the discharged portion of the print is dyed by the reduced vat, and the vat dye becomes fixed on oxidation. A Wash at 160%.F. in.a 0.5% solution of a fatty alcohol sul- As :strong detergent action is used as.

This removal of dye is detrimental,

Application March 26, 1937, Serial No. 133,266

fate or soap is practised to develop the brightness of the vat color. Under such drastic detergent conditions, a considerable loss in strength of the best of the azo type of ground colors occurs, while many less fast colors cannot be used because of their failure to withstand this process- Dyed textile fabrics have been soaked in heavy metal salt solutions in an attempt to improve their fastness to subsequent washings.

the goods which is not only time consumingbut an economic loss. Magnesium and calcium salt solutions have been proposed for use in this connection but have not met withany success since they have little, if any, effect upon the 7 the large volume of washing steps in a print works or a commercial laundry, the importance of this discovery can be realized. The invention is of great importance in the washing of discharge prints where strong detergent and scouring agents are used at elevated temperatures.

This invention has as an object the washing of textile materials. A further object is the -washing of textile fabrics dyed with water-soluble dyes. A still further object isithe washing of textile prints dyed with azo dyes. A still further object is the washing of textile prints under such conditions that color is not removed. Other objects include the washing of discharge prints of dyeingsof water-soluble colors on cotton and viscose rayon, the preparation of washing solutions and compositions, and a general advancement of the art. Still further objects will appear hereinafter.

The above and other objects are accomplished by the following invention which comprises washing textile, and more specifically-dyed textile materials with an aqueous solution containing a Water-soluble alkaline earth metal salt and a detergent compatible therewith. The alkaline earth metal salts are preferably water-soluble calcium and magnesium metal salts such as calcium chloride and magnesium sulfate, and the detergent one which has good scouring properties. In a more limited sense the objects are accomplished by washing discharge patterns on dyeings of direct, after-treated and developed azo colors on cotton and viscose rayon with an aqueous solution containing a water-soluble calcium or magnesium salt and a water-soluble detergent selected from the class consisting of the higher aliphatic hydrocarbon sulfates and the water-soluble salts thereof, and the long chain aliphatic hydrocarbon betaine derivatives. These agents are characterized by being strong detergent and scouring agents.

By the term higher when referring to an aliphatic hydrocarbon radical is meant one containing an aliphatic chain of at least eight carbon atoms. The aliphatic hydrocarbon radicals may be saturated or unsaturated and may be substituted by other groups such as hydroxyl, and halogen such as chlorine groups. As specific examples of aliphatic hydrocarbon sulfates falling within the scope of this invention may be mentioned the water soluble salts of octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and 9, ill-octadecenyl sulfates and mixtures. Among the water soluble salts may be mentioned calcium, magnesium, sodium, potassium, ammonium and amine salts as well as the quaternary ammonium salts. Thus mono, di and tri methyl, ethyl, propyl, isoprcpyl, butyl, cyclohexyl, ethanol, propanol, etc. amines may be used as salt forming groups. Quaternary ammonium salts such as tetra ethyl-, tetramethyl-, triethylmethyl etc. dodecyl, octadecyl and hexadecyl sulfates are especially useful. Other specific compounds which are equivalents to those mentioned will be obvious to those skilled in the art.

Mixtures of sulfates such as those obtained by catalytic hydrogenation of the free fatty acids of coconut oil and sulfation of the entire mixture or fraction as well as those obtained from the sulfation of alcohols obtained by catalytic hydrogenation of palm kernel oil or the free fatty acids thereof and those obtained by sulfating alcohols obtained by saponifying spermaceti, sperm oil, beeswax and distilling are illustrative of suitable mixtures. These and other sulfates are described in Bertsch Patent 1,968,797.

As a general rule the neutralized sulfate products which are sold commercially contain an equivalent amount of free salt. Thus if the sodium salts are dissolved in water a considerable amount of sodium sulfate is present. We have eliminated listing the amount of sodium etc. sulfate present in the following tests for the most part in order that they be more clearly understood.

Among the operative betaine compounds may be mentioned those which contain a long aliphatic hydrocarbon chain, 1. e. from eight to eighteen carbon atoms, attached to either a nitrogen 01' carbon atom of betaine. As examples may be mentioned octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and 9, 10-octadecenyl betaines of the C- and N-types. Other useful specific compounds are listed in Downing and Johnson application Serial No. 13,664 filed March 29, 1935.

In order that our invention will be more clearly understood a brief description of the same in one embodiment, namely the washing of discharge prints, will be given. White discharge prints on dyeings of direct, after-treated or developed azo dyes on cotton and rayon are prepared as follows:

The dyed fabric is printed with a British gum paste containing sodium sulfoxylate formaldehyde. The printed fabric is aged in an atmosphere of steam at a temperature above C. The steam decomposes the sodium sulfoxylate formaldehyde with liberation of the sodium sulfoxylate (NazSOz) which in turn reduces the color into aminoand hydroxyaromatic derivatives. These decomposition products, together with the components of the discharge paste are removed by rinsing the discharge print in a bath containing a higher aliphatic sulfate having eight to twenty-four carbon atoms in the form of a water-soluble salt, together with a water-soluble alkaline earth metal salt. This is best accomplished with an alkali metal mono-alkyl sulfate of a chain length of ten to fourteen carbon atoms or an alkali metal unsaturated aliphatic alcohol sulfate of a chain length of sixteen to eighteen carbon atoms. The preferred metal ions are magnesium or calcium. The higher aliphatic sulfate acts as a detergent or a washing agent to remove the portions of the discharge, while the metal ions prevent the removal of dye from the fabric and prevent bleeding into the discharge portions of the same. It is obvious that any water-soluble alkaline earth metal salt may be used in this process provided it acts to repress the bleeding of the dye from the fabric without exerting a deleterious effect on the dyeing or destroying the detergent properties of the fatty alcohol sulfate. Superior results are obtained with calcium chloride and magnesium sulfate.

Excellent results from the washing process are obtained in solutions containing from 0.25 to 5.0 grams per liter of the higher aliphatic sulfate water soluble salts and higher hydrocarbon substituted betaines and either 0.25 to 10.0 g./l. and preferably 1.0 to 5 g./l. of calcium chloride or 0.5 to 20 g/l. and preferably 2 to 10 g./l. of magnesium sulfate (as epsom salt). Concentrations of 1 gram per liter of calcium chloride and 2 to 2.5 grams of magnesium sulfate greatly and even almost completely repress bleeding of the dye from the goods. The ratio of magnesium sulfate (as epsom salt) to the fatty alcohol sulfate may vary from 0.111 to 40:1 while the ratio of calcium chloride to fatty alcohol sulfate may vary from 0.05:1 to 40:1 provided the metal ion concentration is within the limits described above. The ingredients may be added to the bath either separately or together, in solid form or in solution.

The processing temperature may vary from 80 F. to F. while the ratio of the volume of the bath to goods may vary from 10:1 to 60:1. The washing period should be for at least one minute but may be extended to fifteen minutes or longer, if desired. The conditions described above are the preferred limits but maybe altered to meet any specific requirements which may be encountered.

This invention is not restricted to the use of the fatty alcohol sulfates as detergents. Any detergent having strong scouring properties which is compatible with water-soluble alkaline earth metal salts may be used according to our invention; thus, the higher aliphatic betaine derivatives such as those described in Downing and Johnson application Serial No. 13,664 filed March 29, 1935, give excellent results similar to the higher aliphatic sulfates. Good results are obtained if the alkali metal salts of sulfonated oils, the condensation product of albumin with a .and Platt rapid ager.

fatty acid, and higher aliphatic amidosulfonates such as CnHssCONHCI-IzCHzSOsNa are used to replace the higher aliphatic sulfates in the above described processes. These products are all characterized as agents possessing wetting and detergent properties in solution in the presence of calcium and magnesium salts. The higher aliphatic sulfates and aliphatic betaine derivatives are further characterized as having good scouring properties- Colored discharge prints may be prepared as above .with the additional incorporation of a vat color in the discharge paste. The vat color is reduced by the sodium sulfoxylate in the steam ager, simultaneously with the color on the fabric and replaces the discharged ground color by a dyeing process. The colored discharge print is oxidized in an acid solution (e. g. acetic acid) of sodium perborate or sodium bichromate and is EXAMPLE I A 5% dyeing of Pontamine Navy Blue BF (of Color Index 568 type) was prepared on' .vis-

A discharge pattern of cose rayon piece goods. the dyeing was printed with an engraved roll'la-boratory machine using a discharge, paste containing 20% of sodium sulfoxylate formalydehyde, of gum tragacanth and 5% of-glycerin. The discharge print was aged for five minutes at C. in an atmosphere .of steam in a Mather Thedischarge print was cut into smaller pieces of 3.5 grams each which were washed in various solutions, which are identified in Table I, for three minutes.

TABLE I I dip in cold water, run through squeeze-rolls to remove the excess water, and dried with alhot iron. A'visual examination of the pieces showed that'the strength of the ground color on prints processed in the fatty alcohol sulfate-magnesium or calcium salt baths was appreciably greater- (20% or, more)-,than the strength of the ground color on prints rinsed in a fatty alcohol sulfate solution, in a soap solution or in water ,alone. The differences were more noticeable for prints processed at 160 F. than at F. An exami-.

nation-of the detergent baths following the washingv of the prints also showed that much-more color was removed from the goods in baths which did not contain the added calcium or magnesium, salts in combination with a fatty alcohol sulfate product. This difference in the amount of, color removed from the fabric into the bath has a decided bearing on the appearance of thewhite discharge. The fatty alcohol sulfate-calcium and magnesium salt solutions operated satisfactorily toremove the decomposition products of the discharge together with the discharge paste. There was only a trace staining of the discharged part by bleeding dye even after four prints were washed in the bath. On the other hand, objec.-- tionable heavy bleeding of dye occurred into-the discharge of prints processed in a-fatty alcohol sulfate solution, a soap solution, or in Water alone. This objectionable bleeding occurred with the first print rinsed in the bath. It is apparent, on the basis of the observations given above, that a rinse of the discharge print in a fatty alcohol sulfate-calsium or magnesiumsalt bath is highly advantageous since the ground strength is appreciably stronger and the discharge is much cleaner.

In test baths 24 to 48 the volume of the baths 7 Conditions used for washing prints of Pontcmme Navy Blue BF on mscose rayon Bath MgSOflHzO, C2012, NazSO K1804, Temp., Nglgl- Detergent concentration, g./i. gill. gJL gJL [1' I 0F.

1 Lorol sodium sulfate, 0.5 140 2 do 34 do 140 5-6 Lorol sodium sulfate, 2.5. 140 7 Lorol sodium sulfate, 0.25 160 8-11 Lorol sodium sulfate, 0.5 160 12 Lorol sodium sulfate, 1.0. 160 13-14 Lorol sodium sulfate, 25 160 15 Ocenol sodium sulfate, 0.5 140 16 d 160 17-18 do 160 19-20 Ocenol sodium sulfate, 2.5... 160 Olive oil soap, 2.5 i. 160 22 Olive oil soap, 5.0. Y 160 23 Water 160 24 Lorol sodium sulfate, 2. 2. 5 160 25-26 do 2. 25 2. 75 27-30 do 7. 8 3. 5 i 11. 25 13. 75 160 31 Ocenol sodium sulfate, 2.5 2. 5 100 32-35 do 7.8 3. 5 2.25 2.75 160 36-37 11. 25 13. 75

38 Olive oil soap, 2.5 160 39-40 do 2. 25 2. 75 160 41-42 11. 25 13. 75 160 43-46 Water W 7. 8 3. 5 2. 25 2. 75 160 47-48 11. 25 13. 75 I 160 In test baths 1 to 23, five pieces of the distrolytes and, as a result, the white discharge patcharged dyeing on rayon were rinsed successively in a 200 cc. bath under the conditions specified in Table I. The pieces were stirred continuously with a glass rod during immersion. The prints were rinsed free of the detergent solution bya tern was colored by the bleeding of the dye. This effect became highly pronounced as successive prints were washed in the bath. The addition of any of the inorganic electrolytes served to reduce theremoval of dye from the prints to a degree that varied with the electrolyte used and its concentration in the bath. At equivalent ion concentrations, the calcium and magnesium salts were more effective than the sodium and potassium salts in preventing removal of dye. The calcium chloride at 3.5 g./l. and the magnesium sulfate at 7.8 g./ 1. were more effective than sodium sulfate at 11.25 g./l. or potassium sulfate at 13.75 g./l. At these concentrations the sodium and potassium ions are present at five times the ion concentrations of magnesium and calcium ions in the solutions.

While the potassium and sodium salts decreased the removal of the color from the goods, they also functioned in these experiments to cause redyeing of the discharged portions by the bleeding color. As a result, prints washed in the detergent solutions containing sodium sulfate at 2.25 g./l. and potassium sulfate at 2.75 g./l. were much more intensely colored in the discharged portion than those washed in solutions of the detergent alone. The effect was highly pronounced as successive prints were washed in the same bath. At concentrations of 11.25 g./l. of sodium sulfate and 13.75 g./l. of potassium sulfate the initial prints washed in the detergent solutions were much more highly colored than when processed with the detergent alone. As successive prints were processed in solutions containing these high salt concentrations the discharged portions were highly colored. but not to the degree noted in washing in a solution of the detergent alone.

The calcium and magnesium salts added to solutions of the long chain fatty alcohol sulfate prod ucts not only prevented heavy bleeding of the color from the prints, but also served to prevent redyeing of the white discharge pattern by any color that was removed. As a result, the discharge remained uncolored by more than a trace of the dye as successive prints were washed in the bath and the prints obtained were superior as progressive tests were made in the baths to any prints processed by the detergents alone or with the detergents combined with sodium and potassium salts.

Prints washed in solutions of the electrolytes alone without a detergent were not properly cleansed in the discharge portion. The discharges were appreciably yellow in appearance. While that in washing discharge prints it is not sufficient that an added electrolyte to the detergent bath repress the bleeding of dye from the goods. It is in addition necessary that the inorganic salt act on any removed dye so that it will not be readsorbed on the pattern. It is pointed out that the calcium and magnesium salts are not only more effective than are sodium and potassium salts in preventing the removal of color from dyeings by the detergents with which they are compatible, but that the calcium and magnesium salts also prevent more than a trace of redyeing of pattern effects on the goods by any dye which is removed. The experimental evidence shows that the presence of sodium and potassium salts in the bath at reasonable concentrations does not prevent appreciabie readsorption of dye on the discharge pattern.

The term Lor 1 describes the fraction of saturated alcohols, obtained by hydrogenation of coconut oil, which is composed mainly of C12 and C14 alcohols together with smaller amounts of C16 and C10 alcohols.

The term Ocenol covers a mixture of saturated and unsaturated long chain fatty alcohols, mainly of chain length C16 and C18 and of an iodine number of approximately 60.

Similar results were obtained with the following colors: 8% Pontamine Fast Black PG Extra of the type set forth in U. S. Patent 536,431,

-Pontamine Fast Red 8BL, 6% (Color Index A 2% dyeing of the direct color Du Pont Purpurine 4.3 (Color Index #448) on cotton broadcloth was discharged as in Example I, and cut into small pieces. Comparative tests were made of the efficiency of different detergent compositions, by rinsing gram discharge prints at 80 F. in different detergent baths of composition as given in Table II, for two minutes.

TABLE 11 Conditions for washing discharge prints of direct dyes on cotton Bath r N MESO4.7H20, CaC/h, NazSOl lemp.

1:231 Detergent concentration g /l gfl. gill. 0

l Lorol sodium sulfate, 0.25 80 2 Lorol sodium sulfate, 1.2 80 3-6 Lorol sodium sulfate, 0.120..." 80

7-13 Lorol sodium sulfate, 0.25 80 i i-lg Lorol sodium sulfate, 0.5 80

330-32 Lorol sodium sulfate, 1.25 80 25 Decyl sodium sulfate, 0.08. 80 26 Decyl sodium sulfate, 0.44 80 27-28 Decyl sodium sulfate, 0.08 3 80 29-30 Decyl sodium sulfate, 0.44 so 31 Water No electrolyte. nil 1:, 80

the inorganic salts prevented the substantial removal of dye from the prints, they did not exercise any detergent action.

These latter tests, as well as tests 1 to 23 show These tests were run in 200 cc. of the detergent. The pieces were stirred continuously during the immersion period and then were removed and rinsed with water at l-120 F. to remove the TABLE III Conditions for washing discharge prints of direct mi dyes on cotton Time ggg Detergent concentration, g./l. i? mtin: 1 u es Praestabit oil, 2.5 7. 8 3. 5 i 120 2 Avirol AH extra, 2.5 7. 8 3. 5 120 2 Albumen fatty acid condensation produ 7. 8 3. 5 120 2 CnHxsCON(CH3)OH2OH:SO3N&, 2.5-. 7. 8 3. 5 120 2 N-stenyl betaine, 0.75 7. 8 3. 5 160 3 Olive oil soap, 2.5 120 2 Example I. Five gram pieces of the prints were detergent from the fabric. The pieces were run between squeeze rolls to expel the excess water and were dried with a hot iron. It was shown, as a result. of the tests, thata rinse ina bath washed at 120 F. in baths identified in Table III containing magnesium sulfate and calcium chloride.

containing a fatty alcohol sulfate in combination with a calcium or a magnesium salt produces noticeably better white discharges than does water or solutions of the fatty alcohol sulfate alone.

The bleeding of dye from the fabric in a fatty alcohol sulfate-magnesium or calcium salt bath 7 is less than in water or'in solutions of the fatty alcohol sulfate alone. As a result, the strength of the ground color of prints processed in a fatty alcohol sulfate-calcium or magnesium salt soluwith discharge prints of Pontamine Fast Scarlet 4B3, 2% (Color Index #326, listed as a specific type of color but chemical identity is not revealed) Pontamine Black E, 6% Color Index #581), and Pontamine. Green S Cone, 2% (Color Index #583); The results obtained in the tests again showed that advantages similar to those cited above are obtained when the discharge prints are processed in a bath containing a fatty alcohol sulfate in combination with a calcium or a magnesium salt.

At temperatures of 120 F., similar results were obtained with Du POnt Purpurine 4B (Color Index #448) Pontamine Fast Red 8BL, 2% (Color Index #278), Pontamine Fast Scarlet lBS, 2% (Colorllndex #326), Pontamine Fast Orange S, 2% (Color Index #326, not identified a chemical individual), Pontamine Black E (Color Index #581), Pontamine Fast Scarlet ens, 2% (Color Index #326, chemical identity not given), Pontamine Fast Orange S, 2% (Color Index #326, chemical Pontamine Yellow CG, 2% (Color Index #411) Pontarnine Fast Yellow lGL, 2% (Color Index #349), Pontamine Fast Orange WS, 2% (Color chemical Pontamine Brown CG, 2% (Color Index #598) Pontamine Blue 333., 2% (Color Index #464), Pontamine Green GK, 2% (Color Index #594) Fontamine Black E, 2% (Color Index #581) and Pontamine Green S Conc., 2% (Color Index #583) EXAMPLE III A 2 dyeing Pontamine Blue RW (Color 5. Index #512) on cotton was discharged as in identity not given),-

identity not given) In these tests the white discharge pattern was cleansed to a greater degree using a detergent agent in the presence of the metal ions than by water alone. -When detergent agents were present all of the prints were satisfactorily cleaned to' produce a good white discharge pattern.

Practically no bleeding of the dye occurred into the baths. The discharge patterns processed as above with soap solutions were highly discolored by the bleeding of the dye into the discharged portion. The discharge pattern obtained from the water rinse was dull and tinted by bleeding dye.

in addition to having the advantages listed above were very soft to the feel.

Results similar to those described above were obtained with Pontamine Black E (Color Index #581), Pontamine Green S Conc. (Color Index #583), Pontamine Fast Orange WS (Color Index #326, listed as class), Pontamine Fast Blue 3R (Color Index #464), Pontarnine Fast Orange S (Color Index #326, chemical identity not given), "Pontamine Fast BedSBL (Color Index 2'78) Pontamine Brown CG (Color Index #598), and Pontamine Green GX (Color Index #594).. p

There are a number of direct dyes whose wash fastness is improved by after-treatments, as for exampletreating in a bath containing formaldehyde and acetic acid. This after-treatment is often utilized in discharge Work to improve the fastness of the ground color so that a more vigorous soaping of the discharge print may be used to remove the products of the discharge and the discharge paste. The process for washing prints as outlined above, utilizing fatty alcohol sulfates in combination with calcium and magnesium salts as a detergent medium, has been used advantageously in washing discharge prints on aftertreated dyeings. Forexample:

EICAMPLE IV A 5% dyeing of Pontainine Navy Blue BF (of Color Index 568 type) on rayon was aftertreated wth formaldehyde and acetic acid. A

' discharge print was prepared as in Example I.

Comparative tests were made in, which 3.6 gram pieces of the print were rinsed in detergent baths of the composition outline in Table IV, for

a period of three minutes.

The prints washed'with solutions contain 'ing the higher hydrocarbon substituted betaines' TABLE IV Conditions for washing discharge prints of aftertreated dyes on rayon 53 Detergent concentration, gJl. g i'j fii 55 93 1-2 Lorol sodium sulfate, 0.5 3. 5 140 3-4. Lorol sodium sulfate, 2.5 3. 5 140 57 Lorol sodium sulfate, 0.5 3. 5 160 8-10 Lorol sodium sulfate, 2.5 3. 5 160 11-1 Oceuol sodium sulfate, 3. 160

Ocenol sodium sulfate 2 3. 5 160 Sodium oleate, 5.0 140 do 160 In these tests, five pieces of the discharged dyeing were rinsed successively in a 200 cc. bath under the conditions specified in Table III. The prints were rinsed free of the detergent solution by several dips in cold water, run through squeeze rolls to remove the excess water, and dried with a hot iron. A visual examination of the prints showed that the results obtained were quite similar to those obtained by similar rinses of the unafter-treated dyeing as described in Example I. The strength of the ground color on prints rinsed in a fatty alcohol sulfate-magnesium or calcium salt bath was appreciably (more than 20%) greater than the strength of the ground color on prints rinsed in the soap solution. The differences obtained were greater at 160 F. than at 1e0 E. An examination of the detergent baths following the washing operation showed that much more color was removed by the soap than by the other detergent solutions. The excessive bleeding of the dye into the soap solution was rcflected in a heavy staining of the discharge. The stain became even heavier as successive prints were washed in the bath. On the other hand, there was only a trace staining of the discharge of prints rinsed in a fatty alcohol sulfate-magnesium or calcium salt solution. A comparison of the discharge prints of the after-treated dyeings in this example with discharge prints of the unafter-trea-ted dyeings of the same color under Example I show that of corresponding prints, the appearance of the after-treated was better than the appearance of the unafter-treated samples. However, the results obtained for prints of the unafter-treated dyeing rinsed in a fatty alcohol sulfate-magnesium or calcium salt bath have found limited use in practice not only because of the diificulty in preparing satisfactory discharge patterns on these colors but also because of their poor fastness to soaping in the cus -nary laundry practice. As a result, the developed class of dyes, which possess much better iastness to soaping, has been much more widely used for ground colors in discharge printing. In applying this type of color, a dyeing of a direct dye, containing a diazotizable amino group, is diwith nitrous acid and is coupled with an aromatic or heterocyclic component containing no acid groups. Examples of widely used developers are beta-naphthol, m-toluylene diamine, phenyl methyl pyrazolone. The developed class of dyestuffs does not possess abso lute wash fastness, i. e. an appreciable bleeding of most dyes occurs into a soap solution. As a result the difficulties in processing prints of the direct and after-treated class of dyes are found to occur to a smaller degree with the developed colors. Tests were made in which discharge prints of the developed types of dyes were rinsed advantageously in a bath containing a fatty alcohol sulfate or a higher aliphatic hydrocarbon substituted betaine in combination with a calcium or a magnesium salt. For example:

EXAIVIPLE V A discharge pattern was printed as under Example I on a 3% dyeing of Pontamine Diazo Blue ER (Color Index #517) (Developer betanaphthol) on rayon. Comparative tests were made by rinsing 8.5 gram pieces of the discharge print in detergent baths of the composition given in Table V.

TABLE V Conditions for washing discharge prints of developed dyes on rayon 53 22 Detergent concentration, g./l. 2% rlilitiis- Lorol sodium sulfate, 0.5 160 3 Lorol sodium sulfate, 2.5 160 3 }Lorol sodium sulfate, 0.5 1.6, 4.0, 8.0 2's 160 3 }Lorol sodium sulfate, 2.5 1.6, 4.0,. 8.0 2:3 160 3 Ocenol sodium sulfate, 0.5, 2.5 160 3 }Ocenol sodium sulfate, 0.5 1.6, 4.0, 2 g 160 3 }Ocenol sodium sulfate, 2.5 1.6, 4.0, 8.0 160 3 N -stenyl betaine, 0.15 3. 5 160 3 N-steny], betaine. 0.7 3. 5 160 3 Sodium oleate, 5.0"... 160 3 were vastly superior to the results obtained by treatment of an after-treated dyeing in a soap solution.

The direct dyes as well as dyes which are after-treated with formaldehyde and acetic acid In these tests four successive pieces of the discharge print were processed in detergent baths of 200 cc. volume. The pieces were further rinsed in water at about 110 F. for thirty seconds to remove the detergent solution and then dried with a hot iron. A visual examination of the pieces showed that the white discharge obtained from the initial piece was not greatly different by the various methods of rinsing given in Table V. However, much more bleeding of vdye from the print occurred into the soap solution and into the solutions containing the fatty alcohol sulfatesalone. As a result, the white discharges of successive prints processed in these On the contrary, very little bleeding of thedye occurred in the fatty alcohol sulfate or higher hydrocarbaths became highly stained with dye.

bon substituted betaine salt detergent baths and,

as a result, successive prints rinsed in these, baths remained uniform in quality. The differences nesium or calcium salt bath.

Tests similar to those outlined above were also carried out with Pontamine Diazo Black 'BHSW, 6% (developer meta-toluylene diamine) (Color Index #401). The results obtained in comparative tests with these colors showed an improvement in the fatty alcohol sulfate-magnesium and calcium salt solutions Which varied similar to that described above.

EXAMPLE VI A product containing about 7% of N-octadecyl betaine and about 5% of N-hexadecyl betaine together with smaller amounts ofN-dodecyl betaineand N-myristyl betaine and about 84% of MgSO4.7HzO was prepared by mixing the ingredients in a mortar and pressing into the form of a cake with a hydraulic press under 1000 lbsf/sq. in. pressure. About 0.5 gram of the product was dissolved in 200 cc. of water at 160 F. and the solutions used to rinse white discharge prints of Pontamine Diazo Blue BR. (Color Index #317) as in Example V. The use of the product just described gives results markedly superior to soap for rinsing the discharge prints since practically no bleeding of the dye occurs to decrease the ground strength or to color the White discharge. Similar cakes may be prepared from the individual or mixed higher aliphatic sulfates and higher betaines of the C and N types described early in this case.

A fatty alcohol sulfate together with a magnesiumor a calcium salt was used advantageous- 1y in processing colored discharge prints on rayon. For example:

EXAMPLE v11 A discharge print of Ileucosol Blue G (Color Index 1113) was printed on a 6% dyeing of fPontamine Fast ,PtedflF, (Color Index #419) by the following procedure: The dyeing was printed by means of an engravedroll laboratory machine with a discharge paste containing 20% Leucosol Blue (3, 12.8% sodium sulfoxylate formaldehyde,

tragacanth, 4% glycerin,- and 4% water.

temperature.

15.2% potassium carbonate, 44% British gum The print was aged for five minutes at 105 C. in an 7 atmosphere of steam in a Mather-Flatt rapid ager and was then oxidized for two minutes room temperature in asolution containing 0.5% ofsodium perborate and 0.5% acetic acid at room Comparative tests were made of methods for washing the prints by rinsing 3.5

gram pieces in detergent baths of the composition given in Table VI.

TABLE VI Conditionsfor rinsing colored discharge prints on rayon Bath mum Detergent concentra- MgCl.6HzO Temp, Time,

her tion,g./l. g./l. F. minutes 1 Lrargl sodium sulfate, 6. 45 p 160 5 2 n r' i sodium sulfate, s45 mo 5 s Olive 611 soap, 5.0 160' s In these tests, three successive prints were washed in baths of 200 cc. volume. The pieces were then rinsed at 100 F. in water to remove the'detergent solution and were dried with a hot iron. A visual examination of the pieces showed that the blue discharge portions of prints rinsed in the lorol sodium sulfate-magnesium chloride solutions were appreciably brighter than when rinsed in a soap solution. Very much less bleeding of the ground color occurred in the fatty alcohol sulfate-magnesium chloride solutions than in the soap solution. The improvement in the brightness of the Leucosol Blu'e G discharges obtained by rinsing in the sodium lorol sulfatemagnesium chloride solutions was probably due to the fact that there was much less bleedingof the ground color in these baths. 'It was also observed that the strength of the ground color was appreciably greater on dyeings which were processed in the fatty alcohol sulfate-magnesium chloride solutions. I

Tests similar tothose given above'were carried out with discharge prints of Leucosol Blue G on dyeings of Pontamine Fast Red BBL, 6% (Color Index #278), Pontamine Bordeaux B, 4% (Color Index #375), Pontarnine BlueRW, 4% (Color Index #512), and PontamineFast Yellow 4GL (Color Index #349) all on rayon; An

improvement was observed in the appearance of the discharge prints processed in a fatty alcohol sulfate-magnesium chloride solution which was similar to that described above.

EXAMPLE'VIII ponents as described in Example VII. The print TABLE VII Conditions for rinsing colored discharge prints on rayon Bath Time num- Detergent concentration, g./l. 29%?" min her utes 1-2 Lorol sodium sulfate, 0.5, 160 3 2.5. 3-4 Lorol sodium sulfate, 0.5 7. 8 3. 160 3 5-6 Lorol sodium sulfate, 2.5-". 7.8 3. 5 160 3 78 Ogegol sodium sulfate, 0.5, 160 3 9-10... OcenoI sodium sulfate, o5- 7.s 3 s 160 s Ocenol sodium sulfate, 2.5..- 7.8 3 5 160 3 Olive oil soap, 5.0 140 3 l4 do 160 3 In these tests 3.5 gram pieces of the discharge print were rinsed in 200 cc. of the detergent solution for three minutes, then removed and freed of the detergent by a half minute rinse in water at 110 F. The excess water was removed by squeeze rolls and the print was dried with a hot iron. A visual examination of the prints showed that the strength of the ground color of all prints washed in a fatty alcohol sulfate-magnesium or calcium salt bath was appreciably greater (-20%) than that obtained by processing in a soap solution or in solution of a fatty alcohol sulfate alone. l'he colored discharge portion of the print was of about the same strength and brightness, regardless of the method employed.

EXAMPLE IX A 6% dyeing of Pontamine Diazo Black BHSW (developer meta-toluylene diamine) (Color Index #401) was printed, by means of an engraved roll laboratory machine, with a discharge paste containing Sulfanthrene Scarlet G. of the thioindigo type 19% British gum; 12.8% sodium sulfoxylate formaldehyde, 15.2% potassium carbonate, 4% glycerin and 4% water. The print was aged and oxidized as described under Example VII. Tests of the emciency of dififerent detergent compositions were carried out as described under Example VIII. The results obtained showed that the rinsing of prints in baths containing fatty alcohol sulfates together with calcium or magnesium salts give the same advantages as are described under Example VIII.

The above examples, it will be noted, are directed tothe washing of discharge prints on cotton and rayon and to the making of detergent solutions and detergent compositions in cake form. Our invention is not to be limited to the washing of such white or colored discharge prints, although that represents the preferred embodiment thereof. Discharge printings on silk and Wool may be washed in a similar manner with excellent results.

The process is obviously not limited to the Washing of discharge prints but may be used in washing any colored textile material, especially those with which a detergent action is desired and during which it is desirable to prevent bleeding of the dye from the fabric. The fabrics which may be processed include not only cotton and rayon, but also wool and silk (weighted and unweighted) and fabrics composed of artificial fibers of the cellulose ether and ester type such as cellulose acetate, and any fabrics which may be formed by combinations of these materials. The dyes subject to treatment are not limited to the specific examples and types of colors covered but may be of any that are temporarily or permanently fixed on the fabric by the presence of the metallic ion or ions in the bath. The concentrations of the detergents, the temperatures, and the length of time for processing cover the preferred limits for the invention but do not preclude the use of concentrations outside the limits which may prove better adapted to gain a desired result.

The following examples illustrate the utility of our process in washing dyed fabrics other than discharge prints with the detergent compositions of the present invention.

EXAMPLE X Dyeings on cotton fabrics of (1) Meta tolidine-bis-azo 1 naphthylamine-isulfonic acid (sodium salt) (2) (Color Index #478) ortho tolidine-bis-azo-lnaphthylamine-4sulfonic acid (sodium salt) (3) (Color Index #278) p-sulfobenzene-azobenzene-azo-G-benzoyl-amino-l-naphthol- 3-sulfonic acid (sodium salt) and 1) p-Sulfobenzene-azo-'benzene-azo-6- benzoyl- 1:aminobenzoyl-amino- 1-naphthol-3- sulfonic acid (sodium salt) were rinsed for one hour at 50 C. (120 F.) in

250 cc. of a 1.0 g./l. solution containing a mixture of octyl and decyl sodium sulfates in the proportion of 8 to 3. Corresponding tests were also made in solutions containing varying amounts of calcium chloride and magnesium sulfate in addition to the sodium alkyl sulfate. The results giving the per cent of dye removed by detergent solutions of varying composition are contained in Table VIII.

TABLE VIII Per cent of dye removed by the above alkyl sulfate in admixture with metal salts +MgSO4 +CaClz Dye Alone .005N .OlN .025N .OO5N .OIN

fact that a washing solution can be used for washing a large volume of goods before it needs replacement by a fresh solution. Another advantage resides in the fact that redyeing of the fabric does not occur in our detergent baths. Another important advantage resides in the fact thatv discharge prints and .dyed fabrics which We claim:

The process which comprises coloring a fabric witha water-soluble azo dye, discharging Selected portions of the dye and washing the fabric with an aqueous solution containing a water-soluble alkaline earth metal salt and a detergent compatible therewith which has strong scouring properties taken from the class consist ing of long chain aliphatic hydrocarbon sulfates and higher derivatives.

2. The process which comprises coloring a textile fabric from the class consisting of cotton and viscose rayon with a water-soluble azo dye;

discharging selected portions of the dye with a reducing composition containing a reducing agent, and washing the fabric with an aqueous solution containing a water-soluble alkaline earth metal salt and a water soluble salt of an aliphatic hydrocarbon sulfate having from eight to eighteen carbon atoms.

3. The process which comprises coloring a textile fabric from the class consisting of cotton and viscose rayon with a water-soluble azo dye,

. discharging selected portions of the dye with a reducing composition containing a reducing agent, and washing the fabric with an aqueous solution containing a water-soluble alkaline earth metal salt and an alkali metal salt of an aliphatic hydrocarbon sulfate having from eight to eighteen carbon atoms.

4. The process which comprises coloring a textile fabric with a water-soluble dye, discharging selected portions of the dye with a reducing composition containing a vat dye, oxidizing the vat dye and washing the fabric with an aqueous solution containing .a water-soluble alkaline earth metal salt and a detergent compatible therewith which has strong scouring properties takenv from the class consisting ofhigher aliphatic hydrocarbon sulfates and higher hydrocarbon substituted betaine derivatives.

hydrocarbon substituted betaine tile fabric fromthe class consisting of cotton and tile fabric from the class consisting of cotton,

and viscoserayon'with a water-soluble azo dye, discharging selected portions of the dye with a reducing composition containing sodium sulfoxylate formaldehyde'and a vat dye, oxidizing the vat dye, and washing the fabric with an aqueous solution'containing a water-soluble alkaline earth metal salt and a higher hydrocarbon substituted betaine,

'7. The process which comprises washing dyed fabrics dyed'with a water-soluble dye with an aqueous solution containing an alkaline earth metal salt and a detergent compatible therewith. which has strong scouring propertiestaken from the class consisting of longchain aliphatic substituted betaine derivatives.

8. The process which comprises washing discharge prints dyed with a water-soluble dye with an aqueous solution containing a water-soluble alkaline earth metalsalt and an aliphatic sulfate having eight to eighteen carbon atoms.

9. The process which comprises washing discharge textile prints dyed'with a water-soluble azo dye with aqueous solution containing a water-soluble alkaline earth metal salt and an alkali metal aliphatic sulfate containing a carbon chain of eight to eighteen carbon atoms.

10. A process as set forth in claim 9 wherein the salt is magnesium sulfate.

11. A process as set forth in claim 9 wherein the salt is calcium chloride.

12. The process which comprises washing discharge textile prints dyed with a water-soluble azo dye with an aqueous solution containing an alkaline earth metal salt from the class consisting of calcium and magnesium and a detergent having strong scouring properties taken from the class consisting of. long chain aliphatic sulfates and long chain aliphatic betaine derivatives.

13. A process as set forth in claim 12, wherein the salt is magnesium sulfate.

14. A process as set forth in claim 12 wherein the salt is calcium chloride.

SAMUEL LENHER. JOSEPH E. SMITH.

hydrocarbon. sulfates and higher hydrocarbon j 

